Interactions between cellulose triacetate fiber and organic solvents are discussed with regard to the swelling behavior of cellulose triacetate fiber in many kinds of organic solvents involving chlorinated hydrocarbons such as trichioroethylene, tetrachloroethylene and 1, 1, 1-trichloroethane, important media for solvent dyeing and finishing. Results obtained were as follows:
(1) The results on the equilibrium swelling of cellulose triacetate fiber in solvents showed that the interactions between cellulose triacetate fiber and solvent can be interpreted mainly by dipole force and two kinds of hydrogen bonds in which the solvent behaves as a proton accepter and a proton donor.
(2) The diffusion behavior of solvents in cellulose triacetate fiber involves several kinds of unusual behavior. These are explained by the relaxation of the substrate structure interacting with solvent and the instantaneous internal stress caused by swelling.
(3) From the relationship between the activation energy of diffusion and molecular volume of solvents, it is assumed that dispersion force and π-type hydrogen bond act between cellulose triacetate fiber and solvent.

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Cellulose acetate fibers of various acetyl contents were obtained from the saponification of cellulose triacetate (CTA) fibers with 0.01_??_0.2 N NaOH and 1.0_??_1.8 N HCl solutions. X-ray diffraction and dynamic viscoelastic property of these cellulose acetate fibers were measured and the deacetylation mechanism of cellulose triacetate fibers is discussed in connection with their dyeing behavior.
When CTA fibers were saponified in NaOH solutions, the CTA crystals and α_a absorption due to micro Brownian motion of CTA amorphous molecules disappeared at the same concentration of NaOH solution. This result indicates that deacetylation proceeds annularly from the outside of the fiber as obserbed from the dyeing behavior.
On the other hand, saponification behavior with HCl solutions was fairly different from that of NaOH solutions. In the lower concentration of HCl solutions, saponification reaction didn't take place, but there was a change in the structure of CTA fiber, such as relaxation of the CTA chain molecules. In the middle concentration, the saponified fibers could be dyed with a direct dyestuff, but the CTA crystals still remained. In the higher concentration, the saponification proceeded to the crystalline regions, but the cellulose fibers formed with HCl saponification had a low thermal stability and low crystallinity. The saponification process of CTA fibers with HCl solution, therefore, does not agree with that speculated from their dyeing behavior.

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The property of cellulose acetate pulp must be evaluated by the chemical composition and the reactivity toward acetylation, especially the latter.
The present report describes the successful method of evaluating pulp reactivity for acetylation by measuring the change of light transmittance in the acetylation reaction mixture. Whether pulp is pretreated or not, the reactivity of acetate pulp is very different from that of viscose pulp. It is only by the use of special pulp for acetate that successful acetylation is obtainable.
As the reactivity of pulp is also affected by drying and pulverization, it is necessary to treat pulp carefully.
The acetylation of cellulose is facilitated to some extent by pretreatment with suitable reagents such as acetic acid, etc. The degree of activation by such pretreatment is also evaluated by the present method.

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The swelling region of cellulose triacetate fiber in organic solvents was examined on the basis of the volume term for dye adsorption. Cellulose triacetate fiber swollen in various solvents in the equilibrium states was transferred by solvent exchange into cyclohexane maintaining the swelling region in the solvents, and then the equilibrium adsorption of C. I. Disperse Red 15 from cyclohexane on cellulose triacetate fiber was estimated. The adsorption isotherms obey the distribution law. The relative volume term obtained from the partition coefficients (C_f/C_s, Eq. [1]) by assuming constant affinity reflects the swelling region of cellulose triacetate fiber in the solvents. The swelling region is explained by the interaction and steric effect of solvent. This finding supports the lateral order distribution in the amorphous region of cellulose triacetate fiber.
In addition, the affinity of C. I. Disperse Red 15 to cellulose triacetate fiber obtained in solvent dyeing was corrected with the volume term.

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Acetate, acrylic, polyamide and polyester textiles were deteriorated by microorganisms. We used the same microorganisms and culture mediums as described the preceding paper: six strains of Aspergillus genus (A. flavus, A. sojae, A. niger) and Penicillium genus (P. notatum, P. chrysogenum, P. frequentans). The microbes were incubated with Czapek-Dox agar slant medium, Pfeffer agar slant medium and their modified mediums. The textile fabrics for the test were exposed to the cultures of the microbes and the morphological changes were observed.
Acetate and acrylic textiles were generally deteriorated more easily than polyamide and polyester ones. Three stages of morphological deterioration were observed in the acetate. The threadlike propagation of the microbe in the fiber and the slight swelling were recognized in the first stage (plate 1, 2, 5). In the second stage the acetate suffered the extreme swelling (plate 3, 4, 6). The fiber was degraded thoroughly in the third stage (plate 7). Each strain of Penicillium caused stronger deterioration (swelling) than that of Aspergillus. Plate 8 shows the control of acetate fiber. In the acrylic fiber three stages were observed. The erosion at the surface and the splits along the axis of the fiber were perceived in the first stage (plate 9). In the second stage (plate 10, 11, 12) the splits grew and caused local breaks. The splits ran extensively over the surface of the fiber. As the result the fiber was broken as shown in plate 13 (the third stage). Plate 14 shows the control of acrylic fiber. The deterioration of fibers was observed for all the six strains. These microbes propagated particularly in the splits. The deterioration of polyamide proceeded in the two stages. In the first stage (plate 15) the fiber swelled locally by the erosion. The swelling extreme and the partial breaking occurred as plate 16 (the second stage). The deterioration of polyamide was caused much in the case of the strains of Aspergillus and the use of the insufficient nutrients medium. The deterioration of polyester fiber was similar to the polyamide. The fiber suffered the deterioration by microbes of Penicillium.
The deterioration of these textiles is considered to be by the enzymes produced by the microorganisms.
The textiles were deteriorated in the culture with the insufficients nutrients mediums.
The deterioration of semi-synthetic (acetate) and synthetic (acrylic, polyamide, polyester) textiles was more difficult than that of natural (cotton, wool, silk) and regenerated (rayon) textiles.

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The Central Research Institute, Japan Tobacco & Salt Public Corporation The pressure drop of randomly packed fibrous filter tips for cigarette smoke was studied to establish the relation with the filter properties; kinds of fiber, fiber denier per filament, cross section of fiber, volume fraction of fiber, weight fraction of fibers and filter making method.
On the basis of linear relations found between modified permeability coefficient calculated with equations (2)-(4) and a porosity function, the pressure drop across the fibrous filter tip is given as where the resistance coefficient k=70 and exponent n=1.92 for the model filter. The k value depends on the structural arrangement of the fiber in the filter tip.

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The preparation and characteristics of fibrous ion exchangers composed of vinyl polymers, for example, a strong basic cation exchanger based on styrene-divinylbenzene are studied.
After the impregnated monomer mixture is polymerized in-fiber, the original fiber is dissolved away and ion exchange groups are introduced. For such polymerization process, acetate fiber is found to be suitable as the fiber matrix.
Monomer mixtures studied are styrene-divinyl benzene, vinyl benzyl chloride-divinyl benzene and methy metacrylate-divinylbenzene.
The fiber matrix is dissolved away by treating with 50wt% H₂SO₄ at 85°C for 4 hours. According to the above processes, various fibrous ion exchangers, namely, strong acidic cation exchanger, weak acidic cation exchanger, strong basic anion exchanger and weak basic anion exchanger are prepared.
The characteristics of these fibrous ion exchangers are clarified as follows.
(1) Fiber forms of the fibrous ion exchangers are essentially the same as that of acetate fiber.
(2) Relations between ion exchange capacity, degree of crosslinking and water swelling ratio are essentially the same as those found to corresponding resinous ion exchangers.

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